Using
a Simple Thermal Model to Correct Errors in PRFS MR Thermometry Due to
Heat-Induced Tissue Susceptibility Changes

During MR-guided high intensity focused ultrasound
(MR-HIFU) ablation of fat-containing tissues like the human breast or liver,
heat induced susceptibility changes may give rise to local field
disturbances, leading to errors in PRFS thermometry of the water-based
tissues. A correction method is presented that combines the initial
uncorrected measured temperature change with a thermal model to estimate the
field disturbance and thus correct for these errors. The feasibility is shown
in a porcine adipose tissue and ethylene glycol gel phantom. The maximum
temperature error decreased from 3C before correction to less than 1C after
the correction.